Pedro David Marco:
> Hi,
> Postfix documentation about smtp_fallback_relay says:
>
> smtp_fallback_relay (default: $fallback_relay):
> Optional list of relay hosts for SMTP destinations that can't
> be found or that are unreachable. With Postfix 2.2 and earlier
> this parameter is called fallback_relay.
>
> I have destinations not accepting email with a 451 return code.
> Some of them are being sent by postfix to the smtp_fallback_relay
> and some of them are just sent to the deferred queue... Probably
> i am misunderstanding Postfix documentation but... What is exactly
> the Postfix criteria about using smtp_fallback_relay ????
>
If the mail stays in the Postfix queue, then the smtp_fallback_relay
was not available, or it rejected the mail with a 4XX status, or
you restarted Postfix while it was delivering mail.
You can see that with some logfile analysis.
Wietse
